Congress does not delegate lawmaking, Congress delegates the execution of its powers to the Executive branch. This is how the country has functioned since the beginning, for it would be impractical for it to work otherwise.
Say more: delegation will happen at some level, by definition. In military matters, every step or shot a soldier takes is a decision that has been delegated through a chain of command from Congress. Since Congress is not ever going to be in a position to execute every decision for every individual over which Congress has power, Congress inevitably will delegate the execution of its powers. It has always been this way, and will be this way as long as we have a republic.
